mu - Soul of a tiny new machine. More thorough tests → More comprehensible and rewrite-friendly software → More resilient society.

	Commit message (Collapse)	Author	Age	Files	Lines
*	.	Kartik K. Agaram	2021-04-16	1	-3/+3
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*	explicitly pass data disk to main	Kartik K. Agaram	2021-03-27	1	-1/+1
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*	explicitly pass screen and keyboard to main	Kartik K. Agaram	2021-03-26	1	-2/+2
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*	.	Kartik K. Agaram	2021-03-15	1	-2/+2
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*	7846	Kartik K. Agaram	2021-03-04	1	-1/+1
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*	7842 - new directory organization	Kartik K. Agaram	2021-03-03	1	-0/+31
	Baremetal is now the default build target and therefore has its sources at the top-level. Baremetal programs build using the phase-2 Mu toolchain that requires a Linux kernel. This phase-2 codebase which used to be at the top-level is now under the linux/ directory. Finally, the phase-2 toolchain, while self-hosting, has a way to bootstrap from a C implementation, which is now stored in linux/bootstrap. The bootstrap C implementation uses some literate programming tools that are now in linux/bootstrap/tools. So the whole thing has gotten inverted. Each directory should build one artifact and include the main sources (along with standard library). Tools used for building it are relegated to sub-directories, even though those tools are often useful in their own right, and have had lots of interesting programs written using them. A couple of things have gotten dropped in this process: - I had old ways to run on just a Linux kernel, or with a Soso kernel. No more. - I had some old tooling for running a single test at the cursor. I haven't used that lately. Maybe I'll bring it back one day. The reorg isn't done yet. Still to do: - redo documentation everywhere. All the README files, all other markdown, particularly vocabulary.md. - clean up how-to-run comments at the start of programs everywhere - rethink what to do with the html/ directory. Do we even want to keep supporting it? In spite of these shortcomings, all the scripts at the top-level, linux/ and linux/bootstrap are working. The names of the scripts also feel reasonable. This is a good milestone to take stock at.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Mu - 050_write.subx</title> <meta name="Generator" content="Vim/8.1"> <meta name="plugin-version" content="vim8.1_v1"> <meta name="syntax" content="none"> <meta name="settings" content="number_lines,use_css,no_foldcolumn,expand_tabs,line_ids,prevent_copy="> <meta name="colorscheme" content="minimal-light"> <style type="text/css">  </style> <script type='text/javascript'>  </script> </head> <body onload='JumpToLine();'> <a href='https://github.com/akkartik/mu/blob/master/050_write.subx'>https://github.com/akkartik/mu/blob/master/050_write.subx</a> <pre id='vimCodeElement'> 1 # _write: write to a file descriptor (fd) 2 3 == code 4 # instruction effective address register displacement immediate 5 # . op subop mod rm32 base index scale r32 6 # . 1-3 bytes 3 bits 2 bits 3 bits 3 bits 3 bits 2 bits 2 bits 0/1/2/4 bytes 0/1/2/4 bytes 7 8 Entry: # just exit; can't test _write just yet 9 # . syscall(exit, 0) 10 bb/copy-to-ebx 0/imm32 11 b8/copy-to-eax 1/imm32/exit 12 cd/syscall 0x80/imm8 13 14 _write: # fd: int, s: (addr array byte) 15 # . prologue 16 55/push-ebp 17 89/copy 3/mod/direct 5/rm32/ebp . . . 4/r32/esp . . # copy esp to ebp 18 # . save registers 19 50/push-eax 20 51/push-ecx 21 52/push-edx 22 53/push-ebx 23 # syscall(write, fd, (data) s+4, (size) *s) 24 # . ebx = fd 25 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 3/r32/ebx 8/disp8 . # copy *(ebp+8) to ebx 26 # . var data/ecx: (addr byte) = s+4 27 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 1/r32/ecx 0xc/disp8 . # copy *(ebp+12) to ecx 28 81 0/subop/add 3/mod/direct 1/rm32/ecx . . . . . 4/imm32 # add to ecx 29 # . var size/edx: int = *s 30 8b/copy 1/mod/*+disp8 5/rm32/ebp . . . 2/r32/edx 0xc/disp8 . # copy *(ebp+12) to edx 31 8b/copy 0/mod/indirect 2/rm32/edx . . . 2/r32/edx . . # copy *edx to edx 32 # . syscall 33 b8/copy-to-eax 4/imm32/write 34 cd/syscall 0x80/imm8 35 # if (eax < 0) abort 36 3d/compare-eax-with 0/imm32 37 0f 8c/jump-if-< $_write:abort/disp32 38 $_write:end: 39 # . restore registers 40 5b/pop-to-ebx 41 5a/pop-to-edx 42 59/pop-to-ecx 43 58/pop-to-eax 44 # . epilogue 45 89/copy 3/mod/direct 4/rm32/esp . . . 5/r32/ebp . . # copy ebp to esp 46 5d/pop-to-ebp 47 c3/return 48 49 $_write:abort: 50 # can't write a message here for risk of an infinite loop, so we'll use a special exit code instead 51 # . syscall(exit, 255) 52 bb/copy-to-ebx 0xff/imm32 53 b8/copy-to-eax 1/imm32/exit 54 cd/syscall 0x80/imm8 55 # never gets here 56 57 # . . vim:nowrap:textwidth=0 </pre> </body> </html>